The Auto-UI Organization, ACM and SIGCHI do not issue formal invitation letters for visas to attend ACM sponsored conferences. ACM (not Auto-UI) can however issue a visa support letter. More specifically:
ACM is able to provide visa support letters to attendees as well as authors with accepted papers, posters, or members of the conference committee.
For visa support letters, a requests should be send to firstname.lastname@example.org. Please allow up to 10 business days to receive a letter. All requests are handled in the order they are received. The information below should be included with the request, in order to be completed:
Your name as it appears on your passport
Your current postal mailing address
The name of the conference you are registering for
Your registration confirmation number
If you have any papers accepted for the conference, please provide the title and indicate whether you are the “sole author” or a “co-author”
Authors may indicate their paper title. If no paper, speakers can provide the title of their presentation
ACM does not provide letters for transport of vendor or presenter equipment. ACM suggests shipping the materials insured to the conference facility.